The aim of this work is to analyze cognitive development through a series of studies of anticipatory imagery. Studies are guided by the assumption that operatory development, as understood in Piagetian theory, and process accounts, extent in information processing theories, can be mutually brought to bear on this problem. In one series of experiments, children will be assessed as to their operational understanding of spatial movements which produce imagined results. These same subjects will then be instructed to employ particular cognitive processing behaviors which are thought to facilitate imaginal performance. Results should indicate whether operatory level is prerequisite for utilization of particular processes and how the two interact. The second series is focused on the processes by which children derive imagined states from given, perceptible events. Studies are designed to make transforming activites overt and accessible to measurement. The third series combines both of the above experimental strategies but applies them to nonspatial imaginal tasks. This work should lead to clearer understanding of the development of imaginal processes and their role in intellectual development up to early adolescence.